Thermostatic control device



Febll, 947 J. R. CAMPBELL THERMOSTATIC CONTROL DEVICE 5 Sheets-Sheet l Filed June 25, 1943 Y l. s, ...Qi-V' wf b D: m/M

a C mt s WA e, vs m/m h sY b 5 e n O t Febl1, 1947. J. R. CAMPBELL THERMOSTATIC `CONTROL DEVICE w m. n P mu mm hf a P. C j@ t .t e V SH DS 5 ...im .MS .a #W J 9, *.D 3 M. m .w .m m

5 Sheets-Sheet 3 J. R. CAMPBELL .THERMosTATIc CONTROL DEVICE Filed June 25, 1943 Feb. ll, 1947.

Fi .IZ ,f

lrrventor`il Jame R. Campbe,

b5 H15 Attorney.

Feb- H 94? J. R. CAMPBELL THERMGSTATIC CONTROL DEVICE Filed June 25, 1943 5 Sheets-Sheet 4 wen-bor: James R. CampbeH,

bg His Attorneg.

Fen ,11, 1947.

J. R. CAMPBELL THERIOSTATIC CONTROL DEVICE File'd' June 25, 1943 5 Sheets-Sheet 5 .bn Hu) Inventor: v`James. R. Campbe bg /Vamff Immo ist tt His Attorneg.

Patented Feb.

Jes R. Campbell, Ontario, Calif., assigner to Qeneral Electric Company, a corporation oi New York Application .lune 25, 194.3, Serial No. 492,295

(Cl. 23S- 93) i3 Claims. i

This invention relates to a control device,'more particularly to a control device` for eecting av controlling action on a, fluid re'sponsively to the temperature oi the fluid, and it has for its object the provision of a control device of this character which is of extremely simple and inexpensive construction, and yet which is extremely sensitive in4 its controlling action,

While having a variety of applications, this invention is particularly useful in controlling the rate of flow of a uid as a function of its temperature.

lookingin the direction of the arrows; Fig. 5 is a fragmentary perspective'view, with parts in section, illustrating certain of the elements oi And it is especially useful in controlling the-` temperature of a heated owing fluid by varying the rate of flow of the uid with reference to the heating means. v

The control device arranged in accordance with this invention comprises la fluid control element which in its turn is controlled by means of a turbine which is operated by the flowing fluid. Theblades of the turbine are positioned with reference to'their rotor in accordance with the temperature/ofthe controlled 'uid. Thus, when this temp 'ai-.ure is above a critical predetermined value, the blades are set so as to cause the rotor to rotate in one direction, whereas when the temperature of the iluid is below this critical value they are positionedaso as to rotate the rotor in the opposite direction. The movements of the rotor in the two directions control the control element to eilect a predetermined controlling actionon the fluid.

' Where the device is used to control the rate of ow of the fluid through the heating unit to control the fluid temperature, the control element increases the rate of flow of the fluid should the temperature be too high so that less heat is imparted to it, whereas it decreases the rate of ow if the temperature is too low so as to increase the amount of heat imparted to the ilud; When the uid temperature is at the correct value the blades are set so that the rotor does not move at all andthe control element does not effect any controlling action on the uid which would change its temperature.

-For a, more complete understanding of this invention, reference should be had to the accompanying drawings in which Fig. 1 is a perspective view of an airplane provided with a number of air heating ducts and heating means for heating the air supplied to the ducts, and-the ducts being provided with control units arranged in accordance with this invention so as lto hold substantially constant air temperatures in the ducts; Fig. 2 is a front elevation of a control device embodying this invention and which is utilized in the plane of Fig. 1'; Fig. 3 is a sectional view taken through the line 3-3 of Fig. 2 and looking in the direction of the arrows; Fig. 4 is a sectional view taken-through the line l-l oi' Fig. 2 and the control device of Figs. 2-4; Fig. 6 is a fragmentaryelevation illustrating certain elements of the control device of Figs. 1-5; Figs. 7, 8 and 9 are diagrammatic representations of the turbine rotor wheel and its blades, illustrating various positions of the blades corresponding to various temperatures of the controlled fluid; Fig. 10 is a fragmentary plan view illustrating a portion oi the mechanism shown in Figs. l and 2; Fig. 11 is a vertical sectional elevation view of a modiiied form of this invention; Fig. 12 isa fragmentary vertical sectional view taken through Fig. 1l; Fig. 13 is a fragmentary side .elevation illustrating a portion of the mechanism of Figs. 11 Iand 12; Fig. i4 is a longitudinal vertical sectional View of another embodiment of this invention;

and Fig. 15 illustrates a combined automatic and l manual control arrangement for the uid controlling element.

Referring more particularly to Figs. l-9 inclusive, this invention has been shown as applied to the control of the temperature of the heated air utilized in an aircraft it (Fig. 1) to leat the ernpennage leadingedge rie-icing ducts, wing deicing ducts, turret heaters, gun heatingducts, windshield defrosters, and the like, all of which ducts are denoted in Fig. l by appropriate desig.-

' nations.

'Wing de-icing ducts, and another system for heat-f,

ing 'the air for the lremaining ducts. The first system comprises a heater il which is oi the heat exchanger type, the heat exchanger being heated by the exhaust gases from the airplane motors: the exhaust pipe is indicated by the numeral i2. It will be understood that this heater will comprise an opening I3 through which the air may flow into the system, and that this air in ilowing through the exchanger is heated by the exhaust gases, the heated air owing through a feed duct it and to the wing ducts through a control device It, constructed and arranged in accordance with this invention. The second heating system comprises an air heater It which may be of any suitable' character, such as a gasoline air heater. Air ls fed into this heater by means of a scoop l1, and the heated air ilows through a' control identically the same as the control element I8,

and whichfeeds the heated air to the remaining ducts of the second system, as clearly indicatedin Fig. 1.

Inasmuch as the control elements I5 and i8 are of identically the same construction that ci the element l5 only will be described in detail.

3 The details of construction of this element are shown in Figs. 2-9 inclusive.

As shown in these gures, this control device comprises a relatively short cylindrical duct-like member I9 which is provided on its opposite ends with flanges 2U whereby it may be connected into the controlled duct system, as shown in Fig. 1.

The flow of uid through the duct I9 and hence through the duct system is controlled by means of a pair of shutters 2| and 22 which are mounted in the entrance end of the duct I9, which is the right-hand end of the duct as viewed in Fig. 3. Each of these shutters is of substantially semicircular shape, and it is pivotally mounted to the casin'g I9 by means of shafts 23.' The axis of rotation of each of the shutters is so located that the pressures of the fluid on the shutter areas on opposite' sides of the axis are substantially balanced. The upper shafts 23, as viewed in Figs. 2 and 3, are provided with pulleys 24 located outside of the casing, as shown, and each pulley is provided with a, thread-like groove. Interconnecting the two pulleys is a non-extensible cord 25 which may be formed of any suitable material, such as woven steel wire; this cord has its two ends secured to one pulley by means of a washer 25a and a nut 25h, as shown, and from theseends two lengths 25e of the cord cross each other and are connected to a, loop 25d wound on the other pulley, and which loop is secured to this other pulley by means of a washer 25e and nut lock 25f. Because of this arrangement the cord is reversely wound upon the pulleys, whereby when one of the shutters is rotated, the other is rotated with it, but in'theopposite direction, so that the two shutters swing toward their open and closed positions in unison.

'Ihe right-hand shutter, as viewed in Fig. 2, has a driving shaft 26 extending downwardly from the duct I9, as shown in Fig. 3.. The shaft 26 is driven by suitable temperature responsive control means ,21 which, as shown, is located below the duct member I 9,v as viewed in Figs. 2 and 3. This control comprises an impulse turbine wheel 28 which is provided with a rotor 29 that carries a, plurality of impulse blades 3|! extending ra dially therefrom, as clearly shown in Figs. 3, 4 and 5. The rotor 29 is secured to a shaft 3| which is the output shaft of the temperature control unit and which functions to drive the shutters.

As shownthe rotor 29 is of cup-shape with the blades 30 fastened to the upright -wall of the cup member. This member has a driving connection with the shaft 3| through a friction clutch 32 which comprises a disk 33 which has a tubular section 34 surrounding the shaft 3|. 'I'his section 34 at its top is provided with transverse slots 35 for receiving a pin 33 which extends through an aperture provided for it in the shaft 3| and which, therefore, effects a driving connection between the disk 33 and the shaft 3|. The bottom surface of the bottom wall, of the cup-shaped rotor 29 is pressed firmly against the upper surface of the disk 33 by means of a compression spring 31 which surrounds the sleeve 34 and which has its lower end bearing on the cupped member and which has its top bearing against the projecting ends of the pins 38. The cup-shaped rotor is provided with a dome-shaped cover 33.

The impeller blades 33, as shown, have their inner ends rigidly secured to the upright wall of .the cup-shaped rotor 29, while their outer ends extend radially outwardly from4 this wheel.

l'hese blades are formed of a thermally respon-- sive material, and preferably will be formed of a bimetallic thermostatic material; it will be understood that such material is formed of two metals having dissimilar temperature coefficients of expansion rigidly secured together from end to end and,1which, therefore, function to deflect the blade in one direction or the other, the direction depending upon whether the temperature be elevated or lowered.

The blades 30 are operated by the uid flowing in the duct system and the positions that they take with reference to their rotor depends upon the temperature of this fluid. In order to direct the fluid to the turbine blades and to insure that the fluid delivered is representative of that flowing through the duct system, I provide in the housing |9 a sampling scoop 39 which has an entrance end 40 facing up stream and at which end it has a relatively narrow rectangular section, as shown in Fig. 2, but which extends vertically completely across the full height of the duct. This scoop has a substantially circular discharge port 4I at the bottom of the duct, and connecting the forward opening 40 to the discharge opening 4| are a, pair of side walls 42 and 43 having a curved rear wall 44, as shown, and having a, bottom wall 45 also curved. Furthermore, interposed between the side walls 42 and 43 are a, series of vertically spaced curved guide vanes 46, which divide the entrance end into a plurality of pick-up areas, and which straighten and even out the flow of the various sections of the fluid entering the opening, and also generally direct this fluid down toward the disocharge opening 4|.

It will be observed that the scoop 39 samples fluid from parts of the complete cross-sectional area 'of the duct and thereby insures that the turbine blades are subjected to a temperature which is the average temperature of the fluid flowing through the duct system.

vThe fluid taken by the sampling member 39 and discharged at the opening 4| passes through a duct 41 depending from the bottom of the duct I9 and feeds it into the turbine. This uid first passes through a series of guide vanes 48 which, as more clearly shown in Fig. 5, are generally radially positioned with-reference to the axis of rotation of the turbine 'rotor 29 and which have curved extensions 49 extending outwardly and downwardly over the cover 38 of the rotor and which terminate but a short distance above the plane of movement of the blades 30. 'Ihe upper ends 48 of thes'e guide vanes are rigidly secured to an upper housing 50 provided for the turbine. The lower sections 49 of the guide vanes are secured to an adjustable ring 5| mounted in the housing member 5|i;- for this purpose, each of the sections 49 is provided with an loutwardly extending pin 52 which is secured to the ring 5|. For a purpose which will be described in greater detail hereinafter in connection with the description of the operation of the unit, this ring 5I maybe rotated relatively to the housing 50 to a limited extent, and for this purpose, the ring is secured'to the housing by set screws 53 which, as shown more clearly in Figs. 3 and 5, are threaded into the ring and which are directed through elongated slots 54 provided for them' in the housing 5|) and the heads of which overhang the edges of the slots. It will be understood that when the screws are loosened the ring may be rotated in order to shift the pitions of the vane sections 49 in unison,

' ters.

` dersmodthat if the rate of new be will increase, whereas .if

andere whereas when-the screws are tightened the ring Mating with the top housing wall 5B of the turbine is a bottom housing wall 55 which is secured to the top wall in spaced relation with it by screw fastening means house the turbine' rotor 28 and the radially ex tending blades 30. i

The uid which flows from the varies 58 to t e inner ends of the blades 30 ows radially through the blade section of the from it through the annular outer space between the housing vmembers 50 and 55 into a collector ring T. This ring 51 has a discharge-opening 58 that discharges intoa duct 59 extending downwardly from the bottom wall of the duct lil close tothe'duct di, as shown in Fig. 3, and from this duct it is discharged into the duct It in the down stream `vdirection through a return outlet member 6B.

The rotation imparted to the turbine shaft 3| by the rotation oi' the rotor 28 is used to control the positions of the two shutters 2l and 22, and for this purpose the shaft operatesan output shaft 5l through a reduction gear train 62 which drives a gear segment 62a secured to the shaft' 16|. The'gearing ismounted in a gear housing 63 located belowthe turbine lower housingplate S5, as clearly'show in Fig.- 3. The shaft 6I drives the shutter aft 26 through a suitable over-ride mechanism 6d shown more clearly in Figs. 2-and 6. This mechanism comprises an housing and outwardly the windshield de-frosters and for 56. so that the two walls arm 65 which is rigidly secured ,to the upper endof the shaft 6l and which has an upwardly proijecting section 66 which is adapted to'drive an arm 61 secured to the shaft 26. A coiled tension spring lit/has one' end secured to this arm B1 and its other end secured to the shaft 6i so e arxn 61 against the upright exthat it biases tn tension 66. `Therefore, when theshaft Gl is rotated in* the. direction to open the shutters its extension 66 forces the arm El with it to open the shutters, whereas when the shaft 6I is rotated in the opposite direction to tend to draw the extension 66 away from the arm B1, the spring BB will force the' arm' 61 to follow the extension 6G and will function to close the shut- This over-ride mechanism 6d provides means lfor manually opening theshutters if it should beA desiredl to do so independently of the operation of the turbine and for a-purpose to be described later.

yThe control unit, just described, has for the.

purpose of illustration been shown as applied to control the temperature of the air feed to the various heating ducts of the airplane I0; in each of theheating systems shown vin Fig. 1, the temperature of the air delivered to the ducts iscontrolled by varying its rate of ow with reference to the 'respective heater- -ll or I6. It will be undecreased then necessarily eachunit of air will pick up and will be delivered to In the operation'of the heating the empennage leading edge de=icing vvducts, for the various heating 'ducts connected to the heating system heated bythe heater i6, it will be understood that the air will be introduced into the system by means of the air scoop il. This air will flow through the heater I6 so as to be heated thereby the duct I9 of the control `unit I8, the air owing through this duet, providing the'shutters be in an open position, and thence into the various feed ducts of 'the system. If the temperature ofthe uid owing through the duct I9 be at the desired value, the blades will be straight, as shown in Fig. 8, and the turbine will remain stationary holding the shutters in av corresponding open position.

HoweverQif the temperature should fall below- .the desired value, the blades will curve in the counterclockwise direction from .the position of Fig. 8 to s ome position such as shown in Fig. 7. Here, it is to be noted that the blade curvature shown in Figs. .7 and 9 is somewhat exaggerated for the sake of clarity of illustration. However, they do impulse turbine blades, the air being fed to the blades causing rotation thereof in the direction of the arrow shown-in Fig. 7. This operation of the turbine will rotate the shutters in a direction to move them toward the closed position which will restrict the rate of ow and hence will heat the air to a higher temperature in order to restore it to the desired temperature value. On the otherl hand,` if the temperature should be toov high, the blades will deflect in the other direc'- tion toward some position, such as shown in Fig.

- 9, which will reverse the direction of rotation of the rotor and move the shutters farther toward the open position which will speed up the flow of the air, and thus reduce its temperature. In this way the turbine functions automatically .to hold a desired temperature in the duct system.-

The same is true of the other system shown in Fig. 1, the control l5 operating in precisely the same way to hold the desired temperature in its controlled duct system.

In order to change the temperature setting of' the control unit so as to change the temperature held in the controlled uid, the vanessa are adjusted by the rotatable ring 5l in eith'r direction from its normal central position. When so adjusted the direction of `flow of the uid ap-l mechanism 6d, previously described, is for the more heat from its heater and its temperature the rat'e of new be mcreasedV it will pick up less heatfrom its heater and its temperaturewill be reduced. Theturbine functions to control' the shutters to thus control the rate of ow responsively to the temperature of theair itself that is picked up by the sampling scoop 39 in order to hold substannsuw e nnnstani'.- temperature in' the ain.

purpose of permitting manual opening ofthe shutters, if for any reason it should be desired to lower the temperature in the heating'ducts,

virrespective ofthe condition of operation of the turbine. It is in general, a safety feature, and

is provided to lower the` temperature if for any reason'the control unit should become inoperativev or should not be functioning properly,`and it is provided to prevent overheating of the ducts. It will be observed that in order to thus manually 'open' the shutters it is merely necessary to man- `@system 'for Y curve in the general direction of Fig. '1 and when they curve in. this way they act .as

7 ually move the arm 61 away from its operating projection 69 that is fastened to the operating shaft 6|.

It is to be observed that when the shutters are completely closed, as shown in Fig. 2, the scoop 39 is not closed to the flow of fluid. In other words, the scoop remains open so that iluid can circulate to the turbine whose blades will conbypass located outside of the main fluid duct, as

in the first form of the invention described, but is located directly inthe air stream path.- l

Here, there is provided an outer casing 99 which is' arranged to be inserted directly into the duct of the fluid to'be controlled. For example,y it would be connectedin place of the unit l5 or |8 of Fig. ldirectly into the duct system. The shell ,69 comprises similar end sections 69a and 69h which are secured together at the middlef casing 69 by means of a beading 19 which is clamped on outwardly extending flanges 1| provided on the adjacent ends of the two shell sections, as shown. The shell 69a tapers down to a relatively small entrance opening 12, while the shell 59h tapers down to a similar outlet opening 13.

The inner surface 69o of the curved portion of the shell 69a between its inlet opening 12v and its other end constitutes an outer faring, and coacting with this faring is a wall 14 constituting an inner faring. The controlled fluid is caused to enter the passageway 12 and then is diverted outwardly through the passageway between the inner and oute'r farings. Interposed in this passageway-are a series of-spaced inlet guide vanes 15 which have their planes radially positioned with reference to the longitudinal axis of the casing member 69a, and these vanes coact with the inner and outer farings in order to provide a normal and stream line flow of the fluid as it is about lto leave the shell section 99a.

It will be observed that the shell section 99D is similarly constructed, being provided with inner land outer faring surfaces 16 and 11, and with outlet guide vanes 18. These farings and vanes tend to straighten out the fluid as it flows out of the control unit.

Housed by the casing member B9 and mounted b'etween the two faring sections of the inlet and outlet shells 69a and 99h is a turbine 19 comprising a rotor 89 which is mounted upon a shaft 9|,1 the longitudinal axis of which coincides with the longitudinal axes of the two shell members. The rotor, as shown, has a pan-like shape with its bottom wall 82 positioned vertically and its side wall 83 positioned horizontally. It will further be observed that the side wall 83 in effect joins the two inner faring members 14 and 16, being, in effect, a continuation of these members.

Mounted upon the periphery of the rotor, that is, upon'the side wall 83 are a plurality of im- V 8 the space between the rotor wall 83 and the outer casing between the guide vanes 15 and 18, and therefore, all of the fluid which is caused t-o flow into-this space is caused to move through the blades and into the outlet section 99h.

The shaft 3|` is mounted Vin supports 85 and 86 provided for it on a base member 81.I This -member is provided with a plurality of spaced supporting arms 88 (Fig. l2) which are attached to the outer Walls of the casing 69h.

The shaft 8| is connected to an output or takeoif shaft 89 (Figs. 12 and 13) through a worm gear 99 mounted on the shaft 8| and which meshes with a worm wheel 9|. The worm wheel 9| is mounted on a shaft 92 journaled in base 81 and which drives a. spur`gear 93; and this gear93 meshes with a gear segment 94 secured to the output shaft 89. This gear segment 94-is provided with oppositely positioned arcuate surfaces 95 and 96 which are arranged to coact with a'suitable stop member 91 to limit the arcuate movement of the segment 94 in opposite directions, and hence limit the rotation of the shaft v99 in opposite directions.

It will be understood that in the operation of this form of the invention, the controlled air will flow from the heater into the opening 12, vand it will be constricted by the inner and outer farings and the guide vanes 15 so that it has a normal and stream line flow as it enters the blades 84. It will be further understood that if the fluid does not have the .desired temperature the blades will be deflected in one way or the other so that the turbine will lrotatein one direction or the other to rotate the shaft 99 in one direction or the other, the direction, of course, depending rupon whether or not the temperature is above or below the critical temperature. And it will be further 11nderstood that this motion of the output shaft will be used to control a suitable control element to, restore the temperature to the desired value.

While the fluid control element operated by the shaft 89 has not 4been disclosed in this embodi.

ment, it will be understood that it may be shutters, such as shown in the first form, orit may be any other suitable controlling element.

switch for an operating motor, which motor may be used to drive a shutter connected in the duct. or the motor may be used to control the heating means directly, or effect any other suitable controlling action which will resuit in a control of the temperature of thel fluid.. As shown in Fig. 13, the shaft 89 drives a switch operating arm 98 which coacts with a pair of switches 99 and' |90. It will be understood that these switches may be used to control-a motor or any other suitable controlling agency. For example, they may be used to control the forward and reverse field winding of a'suitable operating motor.

In the form of the invention shown in Fig. 14,

the rotor blades themselves are not formed of the thermostatic material, but a separate thermo-y stat is arranged to rotate with them and it is connected with them in order to change their operative positions relative to their rotor.

As shown. this control device comprises an outer casing |9| formed in sections |92 and |93 which havergenerally the same form and between whichis arranged to rotate a turbine |94. The casings |92 and |93 are shaped in general like the corresponding casings of the second form oi' this invention, the casing |92 having: a relatively small up stream inlet opening '|95 whilethe casing |93 is provided with a relatively small dis- For example, this'shaft may operate a suitable reversing charge "down stream" opening |00. In the inlet opening there is provided an inner faring |01'.

The turbine |04 comprises a cup-shaped rotor |08 mounted upon a shaft |00 which will be journaled in suitable bearings (not shown) provided for it. The turbine further comprises an outer ring which is arranged concentric to the side wall of the cup-shaped rotor |08. And'between the side wall and the` outer ring ||0 are a plurality of impulse blades ||2.

Each blade is mounted upon and secured to a shaft ||3 which has a crank arm ||4 received in an adjustable mount ||5, as clearly'shown-in Fig. 14.

The adjustable mount ||5 is mounted on the inner end of a helically wound thermally responsive member ||6 which has its other, end rigidly secured to a disk-likeplate ||1 which is secured to the shaft |09. The helically wound member HE preferably will be made of bimetallic thermostatic ma-terial so that it will wind and f wind as its temperature changes.

It will be observed that when the position of the mount ||5 is changed by the coil H6 the crank arms llt will be operated to shift .the positions of the shafts I3 and thereby shift, the positions of the turbine blades ||2. The member is provided with a series of apertures IIS so that the fluid entering the unit can pass into the helix ||6 as well as around the outside of it.

In the operation of this form of the invention, it will be understood that when the temperature of the controlled fluid is at the critical value, the thermal member H6 will holdlthe.

blades I2 in such a position that the rotor does not rotate to effect any controlling action. However, if the temperature be above or below the 'critical value the thermal element H6 will wind or unwind, as the case may be, in order tolproperly set the blades ||2 for imparting to the shaft |09 the correct speed and direction of rotation to restore the temperature.

It will be understood. that the shaft |09 will.

drive any suitable control element for controlling the temperature of the uid, such as shut- -lever arm |25 having its lower end, as viewed in AFis'. 15, mounted upon a fixed pivot |26. This arm, as shown, is roughly in the form of a T. The left-hand end |21 of the cross-bar of the T member is mechanically interconnected with the shaft |20 by means of a link |28 which has one end pivoted to the end |21 and its other end pivoted to a crank Iarm |29 which is driven bythe shaft |20. Also arranged in this cross-bar of the T and substantially midway between the ends thereof is a circular notch |30 which is adapted to receive a. roller |3| mounted upon one end of a link |32, the opposite end of which -is pivoted to a lever |33 which drives the shutter shaft |2|.

It will beobserved that as long as the roller |3| is located inthe notch |30, a direct driving connection is effected between the output shaft |20 oi' the control unit and the shutter shaft |2|, and that as the crank arm |29 is oscillated by shaft |20, the. shutter shaft I2| likewise will be oscillated between s hutter open and shutter closed positions. vWhen the roller |3| is in its notch the system functions as does the i'lrst form of this invention.

In order to remove the automatic control from the shutters and to supplant it with the manual control, the roller |3| is removed from the notch |30, and in addition, a fixed cam plate'member |34 is provided which has a plurality of surfaces arranged in predetermined relation for engagement with the roller |3| so as to control the position of the shutters.

The roller |3| is shifted from thenotch |30 and its position thereafter controlled from the manually operated lever |22 by means of a link |35 which at its upper end, as viewed in Fig. 15, supports the roller |3| and which has its lower end pivoted to a vertically adjustable block |36. This block slides in vertically arranged guides |31. The position of the block and hence of the lower end of the link |35 is controlled from, the

lever |22 by flexible cable |38 which has one end connected to the block and its opposite end conindicated by the numeral ||9 and its output shaft is indicated bythe numeral |20. The -control element here is assumed to be the shutter control of the first form of this invention and the shutter operating shaftlis indicated by the numeral |2|.

The shaft, |20 is interconnected mechanically with the shaft |2| for effecting continuous automatic operation of the shutters responsively to the temperature changes of the fluid, and the connection means is controllable at will to remove the shutter shaft |2| from automatic control and to transfer it to a manual control.

Fig. 15.

Theiixed cam plate |38 is provided with a surface |39, and with a slot |00 arranged at an angle to the surface |39, as shown, and which slot has upper and lower guide surfaces Mila and M012, all of which surfaces function to control the actionof the roller. |3|.

In the operation of this over-ride mechanism, it will be understood that when the lever |22 is in its automatic position, as shown, the roller i3| will be located in the notch |30 and the center of movement of the link |35 will -be coincident with the center of movement of the T-shaped lever |27, and that under these conditions there will bea direct mechanical drive from the temperature control unit H9 to theshutters operated by the shaft |2l, and the shutters will be automatically controlled.

Now if it be desired to shift to manual control, the lever is moved in a clockwise direction from its automatic position into its manual range of control. When it is thus moved it elevates the block |36 and thereby removes the roller |3| from the notch |30 and into contact with the surface |30. This operation moves the lever |33 clockwise toward the shutter closed position, the shutters being completely closed when the 11` roller reaches the end of the surface |35 and ls about to enter the slot |40; the member |34A is provided with a guide surface III opposite the surface lMila which draws the roller toward the left and thereby rotates the shutter shaft |2| counterclockwise; this operation of the crank |33 moves the shutters from their fully closed position toward their fully open position, and as the lever |22 is advanced in the clockwise direction the shutters are moved more and more toward their open position, until when the lever reaches its extreme right-hand position indicated "Open on the scale |24, the shutters will' be completely opened. Now if the lever |22 be rotated Vcounterclockwise the roller will engage the surface Hub o'f the slot, `and willv shift the shutter lever |33 clockwise to again move it toward its closed position. I n this way the shutters can be adjusted to arLv position between fully closed and fully opened positions. If it be desired to again place the shutters under automatic control`it is merely necessary to return the lever |22 to its automatic control position Auto.

The cross-bar of the T in its top edge is pro-I vided with a relatively wide, roughly V-shaped notch |42 above the notch |30 so that the member can be oscillated by the control unit |19 when the shutters are under manual control, irrespec-A tive of where the roller I3| happens to be located.

While I have shown particular embodiments `of my invention, it will be understood, of course,

that I do not wish to be limited thereto since many, modifications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

andere curving in one direction when'their temperature is above a predetermined value to cause rotation of said wheel in said one direction and curving in the opposite direction when the Vtemperature is below said predetermined value to cause rotation of said wheel in said opposite direction and said blades taking a position to hold said wheel stationary when said temperature is at said predetermined value, and means for ducting controlled fluid through said blades to control the operation of said wheel.

3. A control device for a duid comprising a turbine wheel provided with temperature responsive operating blades, the positions of said blades with reference to said wheel depending upon their temperature, 'a duct for conveying said fluid, said turbinewheel being located outside of said duct,

a sampling scoop for picking upnuid from said' i duct from various sections of an area extending crosswise thereof, means directing the fluid picked up by said scoop through said blades and then for returning it to said duct, and means controlled by said wheel for controlling the tem.

perature of said fluid.

4. A control device for a fluid comprising a turbine wheel provided with temperature respon.

sive operating blades, the positions of said blades with reference to said wheel depending upon their temperature, a duct for conveying said'fluid, said turbine wheel being located outside of said duct, a relatively narrow sampling scoop extending across substantially the full width of said duct for picking up fluid from said duct from various sections of an area extending normal to the line of flow of said fluid, means for directing the uid picked up by said scoop through said blades and then returning it to said duct, and means controlledby'said wheel for controlling the temperature of said uid.

5. A control device for controlling a flowing uid comprising, a ductthrough which said fluid flows, a turbine wheel in said duct having blades acted upon by the iiowing fluid so as to control the rotation of said wheel, said blades being thermally responsive to the temperature of said fluid so that their positions with reference to the wheel vary with temperature changes both to control the speed of said wheel and also its direcactuated by said'wheel, for controlling the temperature of said fluid.

2. In a-system of fluid flow having means for heating said iiui'd and wherein the temperature of said duid is a function of the rate of now of the fluid with relation to said heating means, means for controlling the flow of said fluid comprising, a flow control member, a turbine wheel, connection means between said wheel and said ow control member for actuating said flow control member to controlling positions to vary said rate of iiow, the wheel when rotated in one direction operating the flow contro1 member to increase the rate of flow of said fluid and when rotated in the opposite direction to decrease the rate of flow-of said fluid, said wheel having actution of rotation depending upon whether said temperature is above or below a predetermined value, a control element actuated by said wheel for controlling the temperature of said fluid, and means for changing the direction of the fluid as it approaches said blades in order to adjust the value of said predetermined temperature.

6. A 'control device for controlling a flowing fluid comprising, a duct through which fluid flows, a turbine wheel in said duct having blades acted upon by the flowing fluid so as'to control the rotation of said wheel, said blades being thermally responsive to the temperature of said fluid so that their positions with reference to theY wheel vary with temperature changes both to control the speed of said wheel and also its direction of rotation depending upon whether said temperature is above or below a predetermined tions of said inlet guide vanos to change said direction of flow and thereby adjust the value of said predetermined temperature.

7. A control unit for insertion into a duid duct to control the dow of iiuid in the duct in accord ance with the temperature of the duid comprising, a duct member constructed and arranged to be connected in the duct and through which the duid will now when connected, a valve movable between open and closed positions to control the flow of duid through said duct member, an impulse turbine wheel with impulse blades thereon, means connecting said wheel with said valve for moving it between said positions, the movement of the valve toward its closed or opened positions depending upon the rotation o said wheel in one direction or the other, means for directing V:iluid dowing in said duct into contact with said blades,

and said blades being formed oi a bimetallic thermostatic material so that their curvature depends upon the temperature of said duid. the

blades curving from a predetermined position corresponding to a corresponding temperature when the temperature of said valve increases to rotate said wheel in one direction and curving in the opposite direction from said predetermined position when the temperature of said fluid decreases so as to rotate said wheel in the opposite direction, and said blades taking a position when the temperature of said duid corresponds to said predetermined temperature so as to hold said wheel stationary.

8. A control device for controlling the rate of I opposite ends secured to said pulleys, said cord thereby providing a driving connection between said shafts whereby when one is rotated the other is driven by it but in the reverse direction, a -turbine wheel connected to said one shaft to drive it, means for directing the controlled duid to dow through the blades of said wheel. and temperature responsive means adapted to respond to the temperature of said duid for adjusting the edective positions of said blades on said wheel in accordance with said temperature.

asians 9. A temperature control device for controlling a dowing fluid comprising, a turbine wheel provided with actuating blades that control the direction of rotation of said wheel and its speed of rotation, dow directing means iorldirecting the controlled fluid through said blades, control means for controlling the rate of dow of said duid, connection means between-said wheel and said control meansfor controlling the operation of said control means to control said rate of dow in accordance with the operation of said wheel, and temperature responsive means adapted to respond to the temperature ot said duid for adjusting the edective positions or said blades on said wheel in order to control the operation thereof either to stop or to rotate and also to control the direction of rotation when it rotates. v

10. A control device for a duid comprising a turbine wheel provided with actuating blades the pomtion o! which is adjustable to vary the speed o! rotation of said wheel and its direction'ot rotation, a duct for conveying said duid, a sampling scoop for pickingup duid from said duct from various sections of an area extending crosswise thereof, means directing the duid picked up by laid scoop through said blades, means op- 4 id erated by said wheel for controlling the temperature of said duid, and tem-perature responsive means adapted to respond to the temperature oi said fluid for adjusting the effective positions of said blades on said wheel both to control the direction of rotation and speed of operation of said wheel.

1i. .A control device for controlling dowing duid y,comprising a turbine wheel having blades acted upon by the dowing duid so as to control the value, a control element .actuated by said wheel i for effecting temperature control of said duid,

and means for controlling. the direction of the duid dow as it approaches said blades in order to adjust the value of said predetermined tem perature.

12. A control device i'or controlling a dowing duid comprising a turbine wheel provided with actuating blades-that control the 'direction of ro tation of said wheel and its speed of rotation, dow directing means for directing the controlled duid through said blades, control means for controlling the rate of flow of said duid, connection means between said wheel and said control means for controlling the operation of said control means tocontrol said rate of dow in accordance with the operation ofsaid wheel, and means responsive to a condition of the controlled duid that is controllable by the rate of dow thereof for adjusting the eilective positions oi said blades on said wheel7 in o rder to control its operation.

13. A temperature control device for controlling a owing duid comprising, a duct through which duid flows, a turbine wheel in said duct having blades acted upon by the dowing duid so as to control the rotation of said wheel, temwheel to hold a substantially constant tempera turein said duid.

JAMESvR. CAlidPBELL.

REFERENCES CITED The following references are of'record in the die of this patent:

UNITED STATES PAfI'EI'BA Number Name Date 2,114,567 Mercur Apr. 19, 1938 2,316,940 .Dewey et al. --.ADL 20, 1943 1,015,552 Gamen Jan. 23, 1912 1,782,073 Piquerez Nov. 18, 1930 1,138,854 *Edgecombe' May 11, 1915 1,724,209 Lieber A118. 13, 1929 2,213,582 Hall Sept. 3, 1940 2,352,786 Hammond, Jr. et al. July 4, 1`i4 2,225,209 Dewey Dec. 17, 1940 

